Spirometer



(No Model,)

W. A. SHEPARD.

SPIROMETER.

No. 331,829. Patented Dec. 8, 1885.

Ni'rnn Snares Pia-TENT @rrrcn \VILLIAM A. SHEPARD, OF ELGIN, ILLINOIS.

SPIROMETER.

gPECIFICATION forming part of Letters Patent No. 331,829, dated December8, 1885.

Application filed February 24, 1885. selial No. 156,814. (No model.)

To all whom it may concern..-

Be it known that I,WILLI.-in A. Snnraan,

of Elgin, in the county of Kane and State of,

Illinois, have invented certain new and useful Improvements inSpirometers; and I do hereby declare that the following is a full,clear, and exact description thereof, reference being had to theaccompanying drawings, and to the letters of reference marked thereon,which form a part of this specification.

This invention relates to that class of spirometers which comprise,generally,a station ar Y receptacle or vessel adapted to contain aquantity of water or other liquid, and a mov able open-bottomed vesselor receiver into which the air ex pellcd from the lungs is forced, saidreceiver being located within the stationary vessel with its side wallsimmersed in the liquid, which thereby forms a water-seal to prevent theescape of air from the interior of the receiver, a suitable index beingusually provided for showing by the upward movement of the receiver thequantity of air entering the latter.

Spirometers of the character above mentioned, as heretofore commonlyconstructed, have consisted of an opentopped stationary vessel havingabottomiaud vertical side walls and a bottomless vessel or receiver ofapp roX'imately the same size and shape as the first vessel, thestationary vessel being, when the device is used, nearly filled withwater, so that when the receiver is at the lower limit of its movement arelatively small air-space will be left between the top surface of thewater and the topof the receiver. In devices constructed in this mannermeans have usually been provided for conveying the air into thereceiver, consisting of a tube extending from the bottom of the vesselupwardly through the liquid therein and opening within the receiverabove the said liquid.

A spirometer constructed as above set forth has been found to beobjectionable for several reasons, the principal ones being that whenthe vessel is filled with liquid to form a seal the apparatus is tooheavy to be conveniently portable, and that the upper end of theinlettube being located below the level of the top wall of the receiverwhen the latter is at the lower limit of its movemenhand consequentlyonly a short distance above the top level of theliquid in the outervessel, the said liquid,in case the apparatus is moved or jarred, isliable to splash over and enter the open end of the said tube. The useof a large body of fluid is also object'oiable on account of the cost ofthe latter when a noncongealable liquid-such as oil or glycerine-isemployed, as is sometimes desirable.

In the device herein shown as embodying my invention the stationary partor vessel of the spiroineter is provided with parallel inher and outerside walls, which form anarrow space closed at its bot-tom and open atits top, for containing the liquid which forms the seal, and betweenwhich the side walls of the receiver are located whenithe parts are inposi (ion for operation. By this construction only the small quantity ofliquid which is contained in the narrow space between the inner andouter walls of the stationary vessel is necessary to form the seal, andthe apparatus will therefore be of little weight when in condition foruse, and may therefore be readily moved or transported from place toplace.

As another feature of improvement in devices of the character described,also, the inlet-tube, which is attached to the stationary vessel andextends upwardly into the space within the movable receiver above theliquid in said stationary vessel, is extended vertically above the topof the receiver, and the latter isprovided with an upwardly-extendingclosed tube surrounding the upper end of the said inlet-tube, wherebyliability of the said liquid entering the tube by the tipping of theapparatus or otherwise will be entirely prevented, as will hereinaftermore fully appear.

The invention may be more fully understood by reference to theaccompanying drawings, in which Figure l is a perspective view of aspirometer constructed in accordance with my invention,with a portion ofthe casing broken away to more clearly show the internal portions of theapparatus. Fig. 2 is a vertical central section of the same.

In the drawings, A represents the exterior vessel or casing of thespiroineter, (herein shown as of cylindric shape,) and B is avertically-movable open-bottomed vessel or receiver, also of cylindricshape, and located within the vessel A. The said vessel A is preferablymade somewhat higher than the receiver B, and is provided at its lowerportion with an inner wall, 0, parallel with the outer or side wall ofthe said vessel A,and con nected about its lower edge with the bottom Aof the vessel A, so as to form a narrow annular space, closed atitsbottom, for containing the water or other liquid to form the seal orair-tight joint between the stationary vessel and the side walls of themovable receiver. The receiver B will in this construction also be ofcylindric shape, and its side walls will preferably be of the properdiameter to enter midway of the space between the inner surface of thevessel A and the inner wall, 0.

As herein shown and preferably constructed, the space within the innerwall, 0, of the vessel will be covered or inclosed by a top or cover, 0,attached to the upper margins of the wall 0, so as to form a closedchamber or air-space, G, which takes the place of the body of waterpresent in spirometers of this class, as heretofore usually constructed.wall 0 will usually be made of approximately the same height as thereceiver, so that when the latter is at the lowerlimit of its movementits top will come in contact, or nearly so,with the top 0 of the chamber0 so that nearly all of the air within the receiver will at such time beexpelled therefrom.

In the particular form of the device herein shown air is admitted to theinterior of the receiver through a pipe or tube, D, located at the baseof the vessel A, and communicating with the chamber C", and an uprighttube, D, attached at its lower end to the top 0 of the chamber 0 andextending upwardly through an aperturein the top of the receiver B to apoint considerably above the said top of the receiver B, said receiverbeing provided with a closed tube, B, surrounding the tube D in its partwhich extends above the top of the receiver, so as to preventthe escapeof air from the receiver at the aperture formed therein for the passageof the said tube D. B is somewhat larger in diameter than the tube D, sothat the said tube B may move freely over the stationary tube D in thevertical movement of the receiver, and. a free space will be formedbetween the tubes for the free upward and downward passage of air fromthe receiver to the top of the tube D. The said tube D will be arrangedto terminate at its upper end at a point which, when the receiver is atits lowest limit of its movement, will leave a space between the openupper end of the said tube D and the closed end of the outer tube, B, sothat the passage from the receiver to the tube D will be at all timesopen.

By the construction above, set forth it will be observed that the airfrom the lower inlettube, D, passes through the chamber 0 beforereaching the receiver. This construction of the parts is not, however,essential, and the tube D may be extended upwardly through The- Thetubethe chamber G and united with the tube D; or, in other words, thetubesD and D may be made continuous, as indicated in dotted lines at DFig. 2, with the same result, so far as the operation of the other partsof the device is concerned. A sufficient quantity of water or otherliquid, indicated at E in the drawings, Will usually be placed in thespace between the outer wall of the vessel and the wall 0, to fill saidspace nearly to the level of the top of the said wall, so that thereceiver may be raised until its bottom is nearly to the top of the wallbefore escape of the air therefrom will occur, whereby the entire areaof the receiver may be utilized. The object of extending the tube Dabove the top of the receiver is to prevent the possibility of anyliquid entering the air-inlet passage, which may, by the accidentaltipping or tilting of the apparatus in moving it or otherwise, flow overthe top 0' of the chamber.

As herein shown, a suitable flexible tube, D provided at its outer endwith a mouthpiece, D is attached to the outer end of the fixedinlet-tube D.

As preferably constructed, the vessel A is made somewhat more than twiceas high as the receiver B, and is provided at its top with a removablecover, A", having in it a central aperture, through which the upper endofthe tube Bextends, and by which the said tube and the upper end of thereceiver are guided in their vertical movement. A suitably divided orgraduated scale or index for showing, by the height of the receiverabove its normal or lowest position, the quantity of air therein ispreferably placed upon the side of the tube B, the index being readagainst the edge of the said cover. Any suitable guide for the upper endof the tube may, however, obviously be used in place of the cover shown,and when the latter is used it will be desirably provided with anaperture, A, to permit the free exit of air from the vessel which isdisplaced by the receiver during the upward movement of the latter.

In the use of a guide for the tube B other than the cover A", the sidewalls of the vessel A may be made to extend only slightly above thelevel of the liquid therein, the top portion of the vessel shownobviously serving only as a support for the cover A, and to incloseand,protect from dust the parts of the apparatus within. it.

Inasmuch as, the liquid forming the seal is liable to be thrown. orforced up between the vessel A and the receiver in case the latter isdepressed faster than the air can escape therefrom through the pipes Dand D, the side walls of the said vessel will preferably in all cases bearranged to extend sufficient] y above the level of the liquid toprevent its overflow under such circumstances.

Although the vessel A is herein shown as of cylindric form, yet it isobvious that, as far as the principles of the invention are concerned,the said casing may be rectangular or of other suitable shape, thereceiver B and the inner wall, 0, in all cases being of the same shapeas the outer vessel, so as to form a relatively narrow space for liquidto form the seal, and to thereby render necessary the use of a smallquantity only of the latter.

The vessel A is, as herein shown, provided with a base formed by afiangeor rim, A, within which the stationary part 1) of the inlettube issupported.

The construction in which the inlet-tubes D and D communicate with thechamber G will usually be preferred, for the reason that by thisconstruction a desirable elastic body of air or air-cushion isinterposed between the month-piece and exit end of the inlet-tube.

The tube D may obviously be made of less length than shown, and, as faras the features of the device relating to the water-seal are concerned,said tube need extend onlya short distance above the top of the chamber0 The construction shown is preferred, however, as by its use anyliability of the entrance of the fluid to the inlet-tube is entirelyobviated.

Aside from the advantages in point of lightness and convenience obtainedby the use of a narrow annular space for the water seal, which have beenhereinbefore pointed out, the construction of the parts in which arelatively-narrow space only is present between the vessel A and theinner wall, 0, atfords a means of holding and guiding the receiver inits upright position without the necessity for the employment ofseparate guides for this purose.

p It is obvious that the principles of the invention may be carried outin devices of other form than herein shown, and I do not desire,therefore, to limit my invention to the exact construction herein setforth, but to cover all devices embodying the general principles ofconstruction embodied in the apparatus herein illustrated and described.

I claim as my invention- 1. A spirometer comprising a stationary vessel,A, having an inner wall, G, forming with the wall of the vesselA aspacefor contain ing liquid to form a seal, the space within said wall 0being covered by a top, 0, and a vertically-movable open-bottomedreceiver, B, located within the said vessel A, substantially as and forthe purpose set forth.

2. In a spirometer, the combination, with l a stationary vessel, A,containing liquid to form a seal, and a vertically-movable openbottomedreceiver located within said vessel A, of an inlettube for the receiverattached to the bottom partof the stationary vessel and extendingupwardly within the latter to a point above the top of the receiver,said receiver being provided with an upwardly-extending closed tube, B,surrounding the upper end of the ,inlettube, substantially as and forthe purpose set forth.

3. A spirometer comprising a stationary vessel provided with an innerwall, 0, forming, with the wall of the vessel, a narrow space forcontaining liquid to form a seal, a vertically-movable open-bottomedreceiver, B, located within the vessel A, and provided with anupwardly-projecting tube, B, closed atits top, and having upon it asuitable index or scale, and an inlettube extending upwardly from thebottom of the stationary vessel within the receiver and the tube B, andterminating Within the latter, substantially as and for the purpose setforth.

at. In a spirometer, the combination, with a stationary vessel, A,having an inner wall, 0, forming, with the wall of the vessel A, a spacefor containing liquid to form a seal, the space within said wall G beingcovered bya top, 0, of a vertically-movable open-bottomed receiver, B,provided with an upwardly-projectiug tube, B, closed at its top, and anair-inlet tube extending upwardly from the top G into the tube B,substantially as described.

5. In a spirometer, the combination, with the vessel A, provided with'an inner wall, 0, in its lower portion and with an apertured removabletop, A", of a vertically-movable receiver, B, provided with anupwardly-ex tending tube, B, having upon it a suitable index or scale,said tube being closed at its top and engaged with the aperture of thetop A and an air-inlet tube extending from the base of the vessel Aupwardly through the receiver and tube B, and terminating within thelatter, substantially as described.

In testimony that I claim the foregoing as my invention I aiiix mysignature in presence of two witnesses.

WILLIAh A. SHEPARD. Witnesses:

WILLIAM GRoT-E, JAS. R. LANE.

